The 6-D data we retrieved for this system also happen to be on the top of our sample accuracy-wise. Based on our simulations performed in Subsection REF , if the binary was indeed born in a nearby open cluster from our sample, we should have been able to detect an unambiguous encounter. Moreover, the spectral type and mass of the companion in the binary (ON6.5 V and 23 M\(_{\odot }\) , [1]} [1]} and [3]} [3]}) tend to discard the case where we would have put too much constraints on the maximum age of the binaries (100 Myr) and missed an encounter that happened before that. This is further supported by [3]} who conclude that LS 5039 actually might bear a black hole, and hence the binary was initially formed by a couple of very massive stars.
